Investigations of Flow Pattern in the SEN Regarding Different Stopper Rod Geometries

Greis, Björn; Bahrmann, Rüdiger; Rückert, Antje; Pfeifer, Herbert

doi:10.1002/srin.201400319

Cited by 4 publications

(3 citation statements)

References 3 publications

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“…Researchers reported this effect on one, and two-phase flows using numerical approaches in the nozzle, verifying the original hypothesis, that biased flows in the mold are due to the slide valve [5][6][7][8][9][10]. Just for having a reference, as it would be conceived, the stopper-rod flow control system yields more symmetric discharging jets in the mold slabs using bifurcated nozzles [11,12]. It is evident that valves with small openings, looking for low casting speeds, will enhance the discharging jets' biased behavior.…”

Section: Introductionmentioning

confidence: 75%

Process Diagnosis of Liquid Steel Flow in a Slab Mold Operated with a Slide Valve

et al. 2020

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Slab molds receive liquid steel from the tundish through bifurcated submerged entry nozzles (SEN) using a slide valve as throughput control. Due to the off-centering position of the three plates’ orifices that conform to the valve to control the steel passage, the flow inside the nozzle and mold is inherently biased toward the valve opening side. In the practical casting, a biased flow induces inhomogeneous heat fluxes through the mold copper plates. The nozzle design itself is also a challenge, and has direct consequences on the quality of the product. A diagnosis of the casting process regarding the internal and external flows, performed through experimental and mathematical simulation tools, made it possible to reach concrete results. The mathematical simulations predicted the flow dynamics, and the topography and levels variations of the meniscus characterized through a full-scale water model. The flows are biased, and the meniscus level fluctuations indicated that the current nozzle is not reliable to cast at the two extremes of the casting speeds of 0.9 m/min and 1.65 m/min, due to the danger of mold flux entrainment. A redesign of the nozzle is recommended, based on the experimental and mathematical results presented here.

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Section: Introductionmentioning

confidence: 75%

Process Diagnosis of Liquid Steel Flow in a Slab Mold Operated with a Slide Valve

et al. 2020

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“…The flow field in the mold is mainly controlled by adjusting processing parameters such as casting speed, immersion depth of SEN, size of the mold, rate of gas injection, slide gate, stopper, [9][10][11][12] and shape of tundish. [13][14][15] Other techniques, such as electromagnetic braking, [16,17] also exist to control the flow pattern in the mold using electromagnetic fields.…”

Section: Introductionmentioning

confidence: 99%

Stabilizing Flow of Molten Steel in Mold during Slab Continuous Casting through Electromagnetic Swirling Flow in Nozzle

Zhu,

Zhao,

et al. 2024

steel research int.

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Bias flow of molten metal in slab mold caused by unstable flow from submerged entry nozzle can deteriorate the slab quality during continuous casting. In this study, a novel electromagnetic swirling flow in nozzle (EMSFN) technique, which utilizes electromagnetic force to stabilize the flow in the nozzle and subsequently control the flow in the mold, is proposed. The mechanism for controlling unstable flow through EMSFN is explored through numerical simulation and water model experiments. In the results, it is shown that the molten steel is rotated under the effect of magnetic field and flows into the mold along the upper edge of the nozzle outlet, which weakens the impact of molten steel on the bottom of nozzle and stabilizes the outflow from nozzle. The flow field is consistently symmetrical on both sides of the nozzle. The impact depth of molten steel flowing down along the narrow sides of the mold on both sides is greatly reduced. The surface velocity on both sides of the nozzle changes uniformly. The range of surface velocity variation with EMSFN is only 10% of that with a conventional nozzle. The EMSFN technique can help prevent slag entrapment and improve the flotation of inclusions and bubbles.

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“…[9][10][11][12][13][14] The stopper rod control system is particularly popular due to its excellent sensitivity. [12] Greis [15] compared three different tip shapes of the stopper rod by a full-scale water model experiment, and the results indicated that the geometry of the stopper rod tip significantly affected the velocity and pressure distribution inside the SEN, potentially influencing the flow inside the mold. Liu [12] compared the CC process data, water model experiment, and numerical simulation prediction under different stopper rod vertical openings to explain the discrepancy between the full-scale water model and the actual caster.…”

mentioning

confidence: 99%

Large Eddy Simulation on Transient Flow Characteristics in a Submerged Entry Nozzle with Different Stopper Rod Locations

Li,

Liu,

Chen

et al. 2024

steel research int.

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A 3D mathematical model combining the large eddy simulation turbulent model and discrete phase model is developed to investigate the influence of the stopper rod location on transient flow characteristics and the deposition of inclusions in a bifurcated submerged entry nozzle (SEN). Transient flow characteristics, including the instantaneous flow pattern, jet speed, vertical and horizontal jet angle, and the backflow zone speed and fraction, are quantitatively compared. Transient jet flow characteristics of the left and right SEN port are almost consistent when the stopper rod is ideally centered. When the stopper rod is offset 10 mm, the discrepancy of the jet speed, vertical jet angle, and backflow zone fraction is 0.12 m s−1, 4°, and 4%, respectively. The horizontal angle and backflow speed are primarily affected by the vortex swirling direction at the bottom region of the SEN well. A positive horizontal jet angle is observed under the counterclockwise vortex, resulting in a higher backflow speed. Conversely, a negative horizontal jet angle and a lower backflow speed are observed when the vortex swirling direction is clockwise. The deposition rate of inclusions on the upper SEN wall is much higher when stopper rod is offset.

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Investigations of Flow Pattern in the SEN Regarding Different Stopper Rod Geometries

Cited by 4 publications

References 3 publications

Process Diagnosis of Liquid Steel Flow in a Slab Mold Operated with a Slide Valve

Process Diagnosis of Liquid Steel Flow in a Slab Mold Operated with a Slide Valve

Stabilizing Flow of Molten Steel in Mold during Slab Continuous Casting through Electromagnetic Swirling Flow in Nozzle

Large Eddy Simulation on Transient Flow Characteristics in a Submerged Entry Nozzle with Different Stopper Rod Locations

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